Bill Clinton’s impeachment may have riveted the country for more than a year, but today it feels like ancient political history. And yet the prospect of Newt Gingrich as the Republican presidential nominee has some people wondering whether we’re in store for another long and ferocious argument about the wisdom–or extreme idiocy–of impeaching the President over his affair with a White House intern. It’s a notion that has former Bush White House speechwriter and conservative thinker David Frum, among others, wringing his hands: Nominating Gingrich, Frum recently wrote, amounts to “volunteering to spend 2012 re-arguing the Clinton impeachment. Who thinks that’s a good idea?”

Possibly no one. Both Democrats and Republicans have reasons to leave the past alone. But maybe no one more than Gingrich himself. Driving Clinton from office for lying about his affair with Monica Lewinsky had the makings of an epic victory that would have made Gingrich, then Speaker of the House, a Republican superhero. But Gingrich badly misread the politics and wound up losing his own job instead. Later, after he was long gone from Congress, Gingrich would lose something less tangible, after he admitted to an extramarital affair of his own.

Clinton’s impeachment, in other words, was a revealing chapter in Gingrich’s life, even if neither party relishes a discussion about it. “It will certainly come up, and in very unfavorable ways” if Gingrich wins the nomination, says Steve Schmidt, a Republican strategist who ran John McCain’s 2008 presidential campaign. For their part, Democrats—especially those named Clinton and those who worked for the former President—aren’t eager to see a new generation of Americans download the Starr Report on their iPads.

Some Democrats say that Newt wasn’t a prime driver of impeachment anyway. “In my mind Newt is probably more associated with the government shutdown” of 1995 says former Clinton spokesman Joe Lockhart, who served during the Lewinsky scandal. “When we think about who was driving the train up there for us, it was Tom DeLay,” who was then the House Republican Whip, “not really Newt.”

It’s true that DeLay was the more determined adversary: The hard-driving Texan felt that Newt would “waffle on how aggressively to press the case against Clinton, lurching back and forth without warning,” according to former Washington Post reporter Peter Baker’s comprehensive book, The Breach: Inside the Impeachment and Trial of William Jefferson Clinton. It’s possible that the adulterous Gingrich was demonstrating discomfort with his own, then secret, position of moral compromise.

Even so, Gingrich was hardly a bystander to the process. “[T]here is no denying that Gingrich is keeping an extraordinarily tight reign” on the House’s proceedings, the Atlanta Journal-Constitution reported in April 1998. Gingrich often negotiated directly with top White House aides, and it was Gingrich who personally rejected a September 1998 offer for Clinton to make a plea-bargain deal that would head off the spectacle of public impeachment proceedings.

Indeed, at times Newt seemed to be enjoying Clinton’s scandal thoroughly. “I will never again, as long as I am Speaker, make a speech without commenting on this topic,” he proclaimed that April. He didn’t wind up making good on that promise, mostly avoiding the public bluster of fervent Clinton-haters like DeLay. But Gingrich did press impeachment as a political issue at a critical—and in hindsight disastrous—moment. On the eve of the 1998 midterm elections, Gingrich ordered a round of harsh television ads on the scandal, in which distressed suburban moms asked one another, “What did you tell your kids?”

Gingrich was confident that the strategy would remind voters of their disgust with Clinton’s philandering. “My firm prediction is that we are [going to win] somewhere between plus eight and plus 30 [seats] in the House,” he declared two days before the election.

Instead, in the worst midterm showing in 64 years for an opposition party, Democrats claimed five seats and left Gingrich’s Republicans with a razor-thin majority and a press narrative that voters were rejecting impeachment. The stunning result prompted an immediate coup against Gingrich, who announced his resignation from the House two days later, on Nov. 5, 1998. Of his critics within the House Republican conference, Gingrich said: “They’re hateful…. They’re cannibals.” Clinton, of course, would be acquitted by the Senate and, buoyed by a booming economy, would finish his presidency with stellar approval ratings.

Gingrich said something else interesting upon his resignation. Referring to his wife at the time, he explained, “Marianne and I are tired. We need time off to get to know each other again.” Gingrich filed for divorce the next July. The following year he married a former House staffer named Callista Bisek, with whom, he admitted in March 2007, he began an affair in the mid-1990s. That affair continued straight through the effort to impeach Clinton.

Trying to smooth the damage of this revelation, Gingrich concedes he fell short of “God’s standards” and has offered creative explanations for his infidelity (including his intense patriotism). But he refuses to admit to hypocrisy. Clinton’s impeachment, he argues, was not about sex–but about lying about sex under oath: “I drew a line in my mind that said, ‘Even though I run the risk of being deeply embarrassed, and even though at a purely personal level I am not rendering judgment on another human being, as a leader of the government trying to uphold the rule of law, I have no choice except to move forward and say that you cannot accept … perjury in your highest officials.”

Still, one doesn’t get the sense that Newt sees his resolute defense of the law as a winning topic. He apparently never raises this momentous chapter of his career, even with hardcore Republican audiences. That’s no surprise, says Steve Schmidt: “When you look back at that period of time, you scratch your head and say what was that about?” he says. “It was zero-sum partisan warfare cloaked in high principle that doesn’t stand the test of time.”

Likewise, loyal Clintonites predict–or at least hope–that they don’t have to dust off thirteen-year-old talking points about the politics of personal destruction. “I don’t think there’s any appetite for it,” says former senior Clinton White House adviser Don Baer. “I think the country has moved on.” If Gingrich’s campaign can sustain the momentum it picked up in December, we may be about to find out whether he’s right.